running real rough and rich

My friend chuck's 89 sc has been running soo rough that it isn't driveable, it wen't down last fall after the mn12 meet. It was running good at the meet, and he ran it on the dyno it showed that it was running pretty rich at that time.
So here's what we've tried so far; replaced fuel press reg, new plugs/ wires, swapped coil pack, mass air sensor, DIS, O2 sensors (one at a time from my car), also the fuel pump is less than 2 yrs old and the cam sensor was replaced last year. It still runs like crap, it smokes black sooty rich exhaust.
Chuck ran some eec code checks but I can't remember what he pulled, I think it pointed to Maf and O2 readings. Any thoughts or ideas?
Is it possible that an injector or two may be stuck open or something?
Please help, thank

i would try some injector cleaner i like stp gas treatment my turbo coupe had an injector hang open once missing and black smoke and stp fixed it in about 1 mile down the road after putting it in it smoothed out and i would unhook battery to reset codes . i put on bigger throttle body and mine idled fast for a week till i unhooked battery.
one time i replaced my battery and it took 3 days before it learned to idle right again it would go down to 500 rpm or stall. i thought something was wrong at first but i knew it ran fine before i replaced battery finally it straightened out after about 3 days driving around

ok granted this was not in my SC, but my '90 Bronco . It was doing almost the exact thing, running so rich that black, wet stuff was coming out of the exhaust. Turned out to be the Coolant Temperature Sensor. under $20 and it runs PERFECT now. I had done a complete tune up, cleaned the IAC valve twice, and finally replaced it.......didn't do O2 sensor cuz that does not affect anything until it's in closed loop (and it was doing it even on cold startup)...so i had given up and called a tech i know at a shop and was gonna bring it to him. He suggested i replace the Coolant Temp Sensor before bringing it to him , as that was the first thing he'd check and it's cheaper than the minimum shop charge.........and he was right!

Someone would have to check, but I seem to recall that the EEC-IV unit has a smart cold start cycle and won't run in cold start mode indefinately if a sensor failure or abnormal reading is input for a extended period. It'll run longer than it would otherwise, but it shouldn't run all the time. At least that was my impression from a post by, I think Dr. Fred.

So after the Fuel Pressure regulator has been verified to not be leaking fuel out it's vaccum port, the next step would be a injector balance test. I don't think it would be real easy on the SC, but typically it is done by using a engine scope, and one by one, pulling the injectors out of service and monitoring engine performance, trying to isolate one or more injectors that have an abnormal impact on performance. But on the SC it's such a pain to do a balance test on the car, the best you can probably get is just a test of the electronics, to ensure the pulse widths sent to each injector is accurate.

Then with the injectors off the car, they can be tested for electronic and mechanical soundness.

Hi. I'm Chuck. Here is a list of the codes I got after doing the KOEO test, KOER, and the cylinder balance test. (which were a pain to do, but it did them)

12) Idle Speed Control motor or Air Bypass not controlling idle properly

21) Engine Coolant Temperature sensor out of range

26) Mass Air Flow or Vane Air Flow out of range

42) System rich

92) System running rich

25) Knock sensor not tested (ignore if not pinging)

This is the order I got them in.

Ouch. That's quite a few. I guess I would start with the Coolant sensor, as that could be the cause of the rich condition due to the engine computer using default or assumption values to allow the engine to run. But the idle control motor code bothers me.

Have you checked all of your connections in the wiring harness. I just wondering if there isn't a bad connection somewhere that is common with the IAC, the MAF and the coolant sensor? Normally the failure of any of them shouldn't send a false signal for the others and the chances of all of them failing at the same time seem remote.

In the mean time you can check the resistance of the sensor. With the engine off, should be 1300(240f) ohms to 7700 ohms(140f). With the engine running it should be 1550(230f) ohms to 4550(170f) ohms.

Well, I changed the coolant temp sensor last night. It didn't help a bit. I'll try the other things you mentioned. If that doesn't work it's gonna get chopped into little pieces and taken to the scrap yard. I'd get more there than trying to sell it on the side of the road.

I'd double check that fuel pressure regulator too.

I just replaced it. I thought that was the original reason it wouldn't start. I think I'll go buy a Camaro. Those are more reliable. Hell, I'd probably have better luck with a Mustang. lol

it would be nice to check the fuel pressure, then you could rule out the regulator and pump. might as well run some really strong injector cleaner thru it too. The cyl balance check said 1,4,6 were suspect using KOER test, right chuck?

Yeah. 1, 4, and 6 were coded to be suspect. I tried starting it yesterday just for the hell of it and all it did was turn over. It didn't even try to fire.